The Clinical Value Of Conventional Ultrasound And Contrast-enhanced Ultrasound In Differentiating Benign And Malignant Thyroid Nodules

Objective:To compare the clinical value of conventional ultrasound and contrast-enhanced ultrasound in differentiating benign and malignant thyroid nodular diseases,to guide clinicians to select reliable diagnostic methods and make relatively accurate diagnosis,and to provide a basis for formulating reasonable treatment programs.Methods:The clinical data of 97 patients with thyroid nodular diseases treated by surgery in our hospital from April 2017 to November 2018 were retrospectively collected.The postoperative pathological examination and diagnosis results of the patients were taken as the gold standard to compare the clinical value and diagnostic accuracy of preoperative conventional ultrasound and contrast-enhanced ultrasound in the differential diagnosis of benign and malignant thyroid nodules.Results:The retrospective study included a total of 97 patients,149 nodules in total.The pathological examination showed 48 malignant nodules and 101 benign nodules.In conventional ultrasound,nodule shape,margins,aspect ratio,echo intensity,microcalcification and suspicious lymph nodes were correlated with the benign and malignant nodules,and the differences were statistically significant?P<0.05?.The uniformity of internal echo was not correlated with the benign and malignant nodules,and there was no statistically significant difference?P=0.102?.Enhanced time,enhanced pattern,enhanced intensity,margins of the enhanced nodules,and rim-like enhancement were correlated with benign and malignant nodules in contrast-enhanced ultrasound,and the differences were statistically significant?P<0.05?.The enhancement uniformity of nodules was not correlated with benign and malignant nodules,and there was no statistically significant difference?P=0.826?.The sensitivity,specificity,accuracy,positive predictive value and negative predictive value of conventional ultrasound were 77.1%?37/48?,78.2%?79/101?,77.9%?116/149?,62.7%?37/59?and 87.8%?79/90?,respectively.The misdiagnosis rate of conventional ultrasound was 21.8%.The sensitivity,specificity,accuracy,positive predictive value,negative predictive valueof contrast-enhanced ultrasound were 87.5%?42/48?,80.2%?81/101?,82.6%?123/149?,67.7%?42/62?and 93.1%?81/87?,respectively.The misdiagnosis rate of contrast-enhanced ultrasound were 19.8%.When comparing conventional ultrasound and contrast-enhanced ultrasound,there were statistically significant differences in terms of sensitivity(?^?17?=10.00,P=0.041)and specificity(?^?17?=5.452,P=0.029)in the diagnosis of malignant thyroid nodules.Conclusion:1.In conventional ultrasound,malignant nodules are characterized by irregular shape,unclear boundary,aspect ratio>1,low or very low echo,microcalcification and suspicious lymph nodes.Benign nodules are characterized by regular shape,clear boundaries,equal or mixed echo and cystic or mixed nodules.However,uniformity of internal echo does not indicate benign or malignant nodules.2.Malignant nodules in contrast-enhanced ultrasound are characterized by the contrast agent entered the lesion slowly,subsided rapidly,hypo-enhancement intensity at peak and unclear margins.Benign nodules are characterized by rapidly entry of the contrast agent into the lesion and subsided slowly than that of the surrounding normal thyroid tissue,clear margins,presence of rim-like enhancement,iso or hyper-enhancement.However,enhancement uniformity of nodules does not indicate benign or malignant nodules.3.Contrast-enhanced ultrasound has high accuracy and clinical value in differentiating benign and malignant thyroid nodules.Although the preferred method of thyroid nodules detection in clinical practice is still conventional ultrasound,contrast-enhanced ultrasound can be used as a supplementary diagnostic method when the results of conventional ultrasound examination show suspicious malignant nodules.